Reading Time: 5 minutes The VMware vCenter upgrade has some possible issue, considering also that the SSO part is changed from the one implemented in vSphere 5.1. VMware has released the vSphere 5.5b (specifically for the vCenter Server application, both installable and vCSA editions) just before the Christmas holiday. Mostly another bunch of fixes around vCenter Single Sign-On functionality and upgrade errors, so be sure to use this one for the upgrade to reduce the possible issues. Note that most of the issues are related to the vCenter components: